Drill bit retriever



Aug. 19, 1958 D. N. MCAULIFFE 2,848,268

DRILL BIT RETRIEVER Filed NOV. 29, 1955 Dennis N. Mc Au/iffe JNVENTOR.

BY non 5 8m United States Patent DRILL BIT RETRIEVER Dennis N. McAnlifie, Little Falls, N. J., assignor of fifty percent to Harry Cambeis, Little Falls, N. J.

Application November 29, 1955, Serial No. 549,732

2 Claims. (Cl. 294-99) The present invention relates to a specially designed retrieving tool which is expressly and suitably designed and otherwise constructed to be successfully and handily employed in fishing for and retrieving lost tools and implements, for example, drill steels, drill bits and the like used in conjunction with pneumatic and equivalent well drilling machines.

Various styles and forms of retrievers have, of course, been devised and used for acceptable and satisfactory tool recovery accomplishments. The obvious object of the instant invention is to provide a simple, practical and economical retriever which, it is believed, is not only worthy of recommendation and endorsement'by those who are economy-minded, but which, and this is more important, may be unqualifiedly endorsed for widespread adoption and use by manufacturers and users.

In carrying out the principles of the invention, a simple open-ended tube of requisite length and cross-sectional dimension is utilized. Provided with an adapter coupling or the like at its upper end, it may be attached to an operating pipe which is utilized for suspending and reciprocating the retriever in an oil well casing during the fishing expedition. The lower end is provided with a novel bellmouth. This is novel in that it is variable in size due to the fact that the wall portions of the bellmouth are split lengthwise to define curvate longitudinally bendable and adaptable gripping fingers.

Another feature has to do with the provision of circumferentially spaced lengthwise slots in the intermediate portion of the tube defining a plurality of relatively narrow strap-like portions. At least one of these portions is bowed to form a curvate gripping bend which 'constitutes the desired friction gripping and retaining -to designate like parts throughout the views:

Figure 1 is a fragmentary view in section showing a well casing, the lost" tool, the retriever, and the manner in which it is used;

Figure 2 is a view in section and elevation on an enlarged scale taken on the vertical line 22 of Figure 1, looking in the direction of t e arrows;

Figure 3 is a cross-section on the line 33 of Figure 2, looking in the direction of the arrows; and

Figure 4 is a bottom plan view emphasizing the aforementioned multiple grip bellmouth.

Referring now to the drawings, and particularly to Figure l, the well casing is denoted by the letter A, and the tool or bit by the letter B.

The improved retriever is denoted, as a structural entity, by the numeral 6. It comprises a length of copper tubing which is open at its respective ends. The upper end portion is conveniently denoted by the numeral 8, and this is described here as the trailing end. The lower end portion 10 continues the leading or distal end. As experimental model was found satisfactory when made from one once copper tubing, 1% inches in diameter, especially when used for retrieving drill steels and water liners used in mining. The preferred embodiment was one foot in length. Wedged and secured in the upper leading end, there is a sleeve-like fitting 12 having an extended fiat-faced internally screw threaded portion 14 providing a tool nut and also a coupling. This serves to accommodatingly attach the screw threaded lower end,

portion 16 of a hollow drill rod or other operating member 18 which is here used for reciprocating the retriever. The lower end portion is bellmouthed, as generally denoted by the numeral 20. In fact, it is formed with longitudinal slits 22 which are closed at their upper ends and open through the lower ends to provide fiaring expandible and contractible grips or fingers. The leading ends of the fingers of the bellmouth are preferably beveled, at least on the interior, as at 24. The gripping fingers are conveniently denoted at 26 and can be either contracted or expanded to do the particular job at hand.

The intermediate portion of the tube is provided with four lengthwise circumferentially spaced slots 28 which are closed at their respective ends and which define circumferentially' spaced lengthwise strap-like members 30. One of these members 30 which is conveniently denoted at 32, is bent inwardly so that the convex surface 34 provides a friction grip which engages the cooperating portion of the tool B.

When using the retriever, it must be attached firmly to a pipe of suitable length here called the drill rod 18. At least two feet, more or less, of rod 18 must be left above the top of the drill hole (not shown). Sometimes, it is desirable to attach what is known as a spud somewhat in the same manner as the same would be used in connection with a regular blow pipe. It is desirable, then, to spread the prongs or fingers of the bellmouth and to insert a bit approximately of the same size and type as the one which has been lost. By tapping or bending the prongs down so that they fit tightly around the shoulder of the bit, the fingers are then in readiness to pick up the lost bit (not detailed). one bit above the surface is used as a pattern for the lost one so that it is possible to adjust the gripping jaws or fingers 25 of the bellmouth. The retriever is then lowered into the drill hole, and if there are drillings on top of the lost bit, it is advisable to connect an air hose to the aforementioned spud and to turn on sufiicient air pressure to blow away the drillings. Then, the hose can be removed and the retriever pressed down until the gripping fingers 26 embrace the upper end of the bit, for example, the bit B, after which the retriever is Worked down and the bit is caused to telescope up into the same until one or more of the bands 32 is frictionally engaged therewith. Now, the retriever and the attached bit may be withdrawn and the bit fished out of the hole in an obvious manner.

It is obvious that after bringing the retriever and the broken drill to the surface, the parts can be separated in any suitable manner and with the aid of other tools or implements (not detailed).

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

In other words,

What is claimed as new is as follows:

1. For use in expeditiously recovering lost drill bits, and the like used, for example, with pneumatic drilling machines, a retriever comprising a tube having a bellmouth at its lower leading end, an adapter at its upper trailing end to accommodate a tubular reciprocable operating member, and friction gripping means intermediate said leading and trailing ends, said bellmouth being provided with lengthwise circumferentially spaced slits having their lower ends opening through the lower leading end of the bellmouth and transforming the latter into a plurality of resilient gripping fingers, the friction gripping means at said intermediate portion embodying at least one lengthwise strap-like member which is bowed inwardly into the bore of the tube to provide a convex friction grip.

2. For use in expeditiously recovering lost drill bits and the like used, for example, with pneumatic drilling machines, a retriever comprising a copper tube open at its upper and lower ends and having its lower leading end provided with a plurality of slots circumferentially spaced and extending lengthwise and opening through 4 i the lower end of the tube and providing gripping fingers, the leading ends of said gripping fingers being flared outwardly and interiorly beveled, the intermediate portion of said tube being provided with at least one pair of spaced parallel circumferential slots defining an intervening strap-like member, the latter being resilient and bowed longitudinally to project into the bore of the tube in a manner to provide a friction grip, and a fitting of sleeve-like form having its lower end fitted telescopically when secured in the upper end of the tube, said fitting being externally fiat-faced to provide a tool grip and internally screw threaded to provide an attaching nut.

References Cited in the file of this patent UNITED STATES PATENTS 526,358 Wisherd i Sept. 18, 1894 995,143 Horn June 13, 1911 1,051,225 Heeter Jan. 21, 1913 1,528,089 Stimpert Mar. 3, 1925 1,793,117 Monroe Feb, 17, 1931 

